function getNewContent(){
    let request = getHTTPObject()
    if(request){
        request.open("GET","../Text/example.txt",true)  //这里txt地址错误会导致请求失败
        request.onreadystatechange = function(){
            if(request.readyState == 4){    //5个可能值，0：未初始化；1：正在加载；2：加载完毕；3：正在交互；4：完成；
                alert('Response Received')
                let para = document.createElement("p")
                let txt = document.createTextNode(request.responseText)
                para.appendChild(txt)
                document.getElementById('new').appendChild(para)
            }
        }
        request.send(null)
    }else{
        alert('Sorry,your browswe doesn\'t suppport XMLHTTP')
    }
    alert('FunctionDone')
}
addLoadEvent(getNewContent)